Projectile currently has several official & unofficial support channels.

For questions, suggestions and support refer to one of them. Please, don't
use the support channels to report issues, as this makes them harder to track.

Gitter

Most internal discussions about the development of Projectile happen on its
gitter channel. You can often find
Projectile's maintainers there and get some interesting news from the project's
kitchen.

Mailing List

The official mailing list is
hosted at Google Groups. It's a low-traffic list, so don't be too hesitant to subscribe.

Freenode

If you're into IRC you can visit the #projectile channel on Freenode.
It's not actively
monitored by the Projectile maintainers themselves, but still you can get support
from other Projectile users there.

Stackoverflow

We're also encouraging users to ask Projectile-related questions on StackOverflow.

When doing so you should use the
Projectile tag (ideally combined
with the tag emacs).

Bountysource

If you're willing to pay for some feature to be implemented you can use
Bountysource to place a
bounty for the work you want to be done.